Just wanted to mention DirtyMarkup – a nice, simple HTML/CSS/JS cleaner. Just paste your code, choose your options and press Clean – and in a few seconds, you get a nicely formatted version of your messy code.
Tag: HTML 5
HTML 5 Please
HTML5 Please is a pretty cool concept.
Whenever your application requires an HTML 5 feature that the user's browser doesn't have, their API shows a nice screen with browsers that support that feature, including newer versions of the user's browser.
A nice way to get people to update when the new features would actually be useful.